1. Field of the Invention
The present invention relates to a disc brake for a vehicle incorporated into an automobile or motorcycle. More particularly, the present invention relates to a pin-slide type disc brake for a vehicle.
2. Description of the Related Art
The pin-slide type disc brake is typically composed as follows. A caliper body, to which an acting section provided on one side of a disc rotor and a reacting section provided on the other side of the disc rotor are integrally connected by a bridge portion which strides across the outside of the disc rotor, is supported by a caliper bracket, which is fixed to a vehicle body at one side portion of the disc rotor, by a pair of slide pins so that the caliper body can slide in axial direction of the disc, and a pair of frictional pads are arranged between the acting section and the reacting section while the disc rotor is being interposed between the pair of frictional pads, and further a torque receiving section for receiving a braking torque given from the frictional pads is provided in the caliper bracket. The disc brake for a vehicle is fixed to the vehicle body in such a manner that mounting holes for mounting bolts are formed in the vehicle attaching section provided in the caliper bracket and the caliper bracket is fastened to the vehicle body by mounting bolts which are inserted into the mounting holes for mounting bolts.
Torque receiving faces for receiving a braking torque given from the frictional pad are provided on both sides of the caliper bracket in the circumferential direction of the disc rotor being opposed to each other. A torque transmitting section, which is formed in the frictional pad, is made to contact with the torque receiving face so that the braking torque given from the frictional pad can be received by the caliper body. (For example, see Japanese Patent Unexamined Publication no. JP-A-2004-28304.)
In the disc brake described above, the vehicle body attaching section of the caliper bracket at a rotation come-out side, which is defined such that a portion of the disc rotor near the rotation come-out side moves apart from the caliper body when the vehicle runs forward, is arranged close to the torque receiving section, and the mounting bolt is attached close to the torque receiving section. On the other hand, the vehicle body attaching section at a rotation come-in side, which is defined such that a portion of the disc rotor near the rotation come-in side approaches to the caliper body when the vehicle runs forward, is arranged on the inner circumferential side of the disc rotor in respect to the torque receiving section, and the mounting bolt is attached at a position apart from the torque receiving section. Therefore, at the time of braking, the caliper bracket is given a load in such a manner that the caliper bracket is tilted and twisted. Accordingly, the brake feeling is deteriorated. Further, there is a possibility that the frictional pads are partially abraded and disadvantageously dragged. For the above reasons, it is necessary to enhance the attaching strength of the caliper bracket to the vehicle body so as to prevent the tilt and twist of the caliper bracket in the axial direction of the disc. Therefore, in the related art, the wall thickness of the caliper bracket must be increased, which increases the weight and the size of the caliper bracket. As a result, the manufacturing cost of the disc brake is raised.
Moreover, in the disc brake described above, the friction pads, a reacting pawl provided on the reacting section and a portion of the caliper bracket located on the reacting section side are composed into a complicated shape in which recess portions and protruding portions are formed. Therefore, when the disc brake is used in a condition in which earth and sand tend to get into the periphery of the disc brake, the earth and sand, which have gotten into the periphery of the friction pad, are caught by the complicated recess portions and protruding portions. Accordingly, it becomes late that the earth and sand are discharged from the periphery of the friction pad, and the earth and sand temporarily stay in the periphery of the friction pad. In this case, although it is a temporary phenomenon, the friction pad bites the earth and sand, and the brake feeling is deteriorated and further the dragging of the friction pad occurs.